Texas Rangers star pitcher Yu Darvish has been thrown a curveball: Major League Baseball is investigating his bookie brother.

Sho Darvish was arrested by Osaka police last October for running an illegal baseball betting ring, allegedly taking thousands of low-stakes wagers (10,000 yen is roughly $85 dollars) on games in MLB and Japan’s own Nippon Professional Baseball league, according to The Japan Times.

“We are aware of this situation and are looking into it, per our standard protocols,” MLB’s vice president for communications Michael Teevan told the newspaper. “Our efforts are ongoing, and as such I am not at liberty to go into what they entail.”

The report said it was unclear whether Sho Darvish took action on any Rangers games. Yu Darvish could have aided his brother — willingly or inadvertently — by passing along insider information.

Pete Rose was banned from baseball for his gambling activities. Pirates lefty Jeff Locke and Marlins righty Jarred Cosart have been subjected to gambling investigations in recent years — for game-fixing and betting, respectively, according to Yahoo — though both players were completely cleared.

Yu Darvish, 29, received a six-year, $56 million contract from the Rangers before the 2012 season. He went 39-25 with a 3.27 ERA in three seasons, striking out 680 in 545 1/3 innings, before missing all of last season due to Tommy John surgery.